A typical flow cytometer detector has a limited collection range. In quantitative terms, the collection range for a typical flow cytometer with a photomultiplier tube is approximately four decades, whereas the signal range of the objects may span more than five decades across experiments. In simple terms, the collection range of a typical flow cytometer is smaller than the signal range of the objects. For this reason, the typical detector is supplied with a gain level for the photomultiplier tubes and/or an amplifier. Detectors typically collect data relative to an object's size (light scatter) or brightness (fluorescence); both types of data are often collected on each object detected. To collect signals from small or faint objects, the gain level is increased. With an increased gain level, however, the signals from large or bright objects are too intense to be collected. To collect signals from large or bright objects, the gain level is decreased. With a decreased gain level, however, the signals from small or faint objects are too weak to be collected.
As shown in FIG. 1, the typical flow cytometer user interface involves the preparation and running of a pilot sample in order to appropriately set the gain control and define the user-set collection range. This involves the steps of (1) setting the gain control to what the user predicts will provide the desired collection range, (2) running a pilot sample through the flow cytometer, (3) viewing the pilot data/signal collected from the pilot sample, (4) identifying the extent to which, if any, the gain setting should be modified to achieve a more suitable collection range, and (5) repeating steps 1-4 as needed until the desired collection range is achieved. Since the typical detector is unable to obtain useable data from signals beyond its collection range, and since the typical detector requires a pre-set gain level, the typical user interface does not allow the user to adjust the signal gain level/scaling (e.g. photomultiplier tube voltages) after data acquisition is complete. Observing data signals outside of the pre-set collection range is only possible if (1) the user changes the detector gain levels and (2) the user is able to run an additional test sample that is relatively homogenous to the previous samples and is temporally stable.
The limitations of the user interface of typical flow cytometer systems have at least four disadvantages: (1) the expenditure of valuable user time spent on the gain-setting process to ensure it is set correctly; (2) the requirement of significantly more sample to determine the proper gain settings (i.e. more sample is used setting the gain than is actually used in the data collection run), (3) the potential loss of valuable data because the user incorrectly anticipated the actual signal range and a portion or more of the input signals are outside the user-set “active” dynamic collection range and are not collected; and (4) the inability to observe and “undo” changes in user-set gain/scaling settings without running additional samples.
As flow cytometer systems incorporate features that significantly increase the collection ranges to a range that approaches the object signal ranges (e.g. broad dynamic range flow cytometers), there will be a need in the flow cytometer field to create a new and improved flow cytometer user interface that avoids or minimizes one or more of these disadvantages. This invention provides such new and improved flow cytometer user interface.